DESCRIPTION

The bkgrndset and wbkgrndset routines manipulate the
background of the named window.
The window background is a cchar_t consisting of
any combination of attributes (i.e., rendition) and a complex character.
The attribute part of the background is combined (OR’ed) with all non-blank
characters that are written into the window with waddch. Both
the character and attribute parts of the background are combined with
the blank characters.
The background becomes a property of the
character and moves with the character through any scrolling and
insert/delete line/character operations.

To the extent possible on a
particular terminal, the attribute part of the background is displayed
as the graphic rendition of the character put on the screen.

The bkgrnd and wbkgrnd functions
set the background property of the current or specified window
and then apply this setting to every character position in that window:

The rendition of every character on the screen is changed to
the new background rendition.

Wherever the former background character
appears, it is changed to the new background character.

The getbkgrnd function returns the given window’s current background
character/attribute pair via the wch pointer.

NOTES

Note thatbkgrnd,bkgrndset, andgetbkgrnd
may be macros.

RETURN VALUES

The bkgrndset and wbkgrndset routines do not return a value.

Upon successful completion, the other functions return OK.
Otherwise, they return ERR.
A null window pointer is treated as an error.